Method and device for the electrolytic treatment of electrically conducting structures which are insulated from each other and positioned on the surface of electrically insulating film materials and use of the method

ABSTRACT

For electrolytic treatment of electrically mutually insulated, electrically conductive structures  4  on surfaces of electrically insulating foil material (Fo), is unloaded from a store  15′, 15″ , transported on a conveying line through a treatment unit  1  and brought in contact with treatment fluid F 1 . During transportation, the material Fo is guided past at least one electrode arrangement, having at least one cathodically polarised electrode  6  and at least one anodically polarised electrode  7 , both being brought in contact with the treatment fluid F 1  and being connected to a current/voltage source  8 . Current flows through the electrodes  6, 7  and the electrically conductive structures  4 . The electrodes  6, 7  are screened from each other so that substantially no electric current is able to flow directly between oppositely polarised electrodes  6, 7 . The material Fo is finally loaded back onto a store  15′, 15″.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a method and device for electrolytic treatmentof electrically mutually insulated, electrically conductive structureson surfaces of electrically insulating foil material and applications ofthe method.

2. Description of the Related Art

Electroplating processes among others are used for metal coating ofstrips. For quite a number of years, so-called reel-to-reel treatmentunits have been used for this purpose, the material being transportedthrough said units and, during transportation, coming into contact withtreatment fluid.

A method for electrolytic etching of aluminium foil is described in U.S.Pat. No. 3,779,877 in which the foil is firstly guided over anodicallypolarised contact shoes and then guided into the electroplatingtreatment baths. In the treatment baths, the foil is guided pastcathodically polarised electrodes and then taken out of the bath again.The foil is thereby guided once again over anodically polarised contactshoes.

Another method for treating metal strips, metal wires or metal profilesis described in EP 0 518 850 A1 in which method the electricallyconductive item to be treated is guided through two containers filledwith aqueous electrolytes one after the other for electrolytic pickling,an anodic treatment in the second container following a cathodictreatment in the first container. Current from an electrode in the firstcontainer is directed thereby over the item to an electrode in thesecond container so that, by means of the item to be treated, a circuitis completed between the electrodes of a different polarity, saidelectrodes being located in the successive containers. In alternativeembodiments, oppositely polarised electrodes can also be provided in onetreatment container and further electrodes in additional containers.

Furthermore, a method is known from EP 0 093 681 B1 for continuouscoating of wires, tubes and other semi-finished products made ofaluminium with nickel. In this method, the semi-finished product isfirstly conveyed into a first bath container and then into a second bathcontainer. In the first bath container, the semi-finished product isguided past a negatively polarised electrode and, in the second bathcontainer, guided past a positively polarised electrode. A metallisingbath is situated in the bath containers. As a consequence of the factthat the semi-finished product is electrically conductive and, at thesame time, is in contact with both metallising baths, the circuitbetween the electrodes, which are connected by a current source, iscompleted. In contrast to the negatively polarised electrode in thefirst bath container, the semi-finished product is anodically polarised.In contrast to the positively polarised electrode in the second bathcontainer, the semi-finished product is on the other hand cathodicallypolarised so that metal can be deposited there.

A method is known from EP 0 395 542 A1 for continuous coating of asubstrate, which is made of graphite, aluminium or its alloys, with ametal, the substrate being guided successively through two containers,which are connected to each other and contain an activation bath or ametallising bath, a cathode being disposed in the first container and ananode in the second container. Using this method, rods, tubes, wires,strips and other semi-finished products can be coated as substrates.

A fundamental disadvantage of the above-mentioned methods resides in thefact that only whole-surface conductive surfaces can be electrolyticallytreated but not electrically mutually insulated structures.

As a solution to the latter problem, a method has been proposed in WO97/37062 A1 for electrochemical treatment of electrically mutuallyinsulated regions on printed circuit boards. Accordingly, the printedcircuit boards, which are brought in contact with the treatmentsolution, are brought in contact successively with stationary brushelectrodes, which are supplied from a current source so that anelectrical potential can be applied to the individual electricallyconductive structures. An electrical potential is applied between thebrushes, which are preferably formed of metal wires, and the anodes,which are disposed between the brushes.

This device has the disadvantage that the brushes are completely coveredwith metal within a very short time since approximately 90% of the metalis deposited on the brushes and only 10% on the regions to bemetallised. Therefore, the brushes must be freed again of metal afterjust a short operational time. For this purpose, the brushes must bedismantled again from the device and be freed of metal or elseelaborately constructed devices need to be provided which help to removeagain the metal on the brushes by means of electrochemical polarityreversal of the brushes to be regenerated. In addition, the brush endscan easily damage fine structures on the printed circuit boards.Likewise, the brush material thereby wears quickly, the finest particlesbeing rubbed off and getting into the bath where they lead to damageduring metallisation. Especially for metallising very small structures,for example those with a width or length of 0.1 mm, there must be usedbrushes with very thin wires. These wear especially quickly. Particleswhich come from the worn brushes then proceed into the bath and into theholes of conductive foil and produce significant defects.

In other known methods for metallising electrically insulatedstructures, currentless metallising processes are used. However, thesemethods are slow, difficult to implement and expensive since fairlylarge quantities of chemical substances are used. The used substancesare frequently environmentally damaging and therefore incur furthersignificant costs in disposing thereof. In addition, it is not ensuredthat only the electrically conductive structures are metallised. It isoften observed that, in this case, the metal is also deposited on theelectrically insulating surface regions which lie between, resulting inrejection.

A method is described in EP 0 838 542 A1 for electrolytic pickling ofmetallic strips, especially high quality steel strips, strips made oftitanium, aluminium or nickel, the electrical current being directedthrough the bath without electrically conducting contact between thestrip and the electrodes. The electrodes are disposed opposite the stripand polarised cathodically or anodically. It has emerged though that, inthe implementation of this method, the current yield in an electrolytictreatment is very small.

Finally, a device is disclosed in Patent Abstracts of Japan C-315, Nov.20, 1985, Vol. 9, No. 293, JP 60-135600 A for electrolytic treatment ofa steel strip. The strip is guided through an electrolytic bath for thispurpose between oppositely polarised electrodes. In order to prevent anelectrical current flow between the oppositely situated and oppositelypolarised electrodes, shielding plates are provided between theelectrodes in the plane in which the bath is guided.

The problem underlying the present invention is therefore to avoid thedisadvantages of the known electrolytic treatment methods and inparticular to find a device and method with which a continuouselectrolytic treatment of small electrically mutually insulated,electrically conductive structures on surfaces of electricallyinsulating foil material is possible at low cost, it also requiring tobe ensured that the equipment costs are low and that the method can beimplemented with adequate efficiency. In particular, the method and thedevice should be able to be used for the production of conductive foilsin printed circuit board technology.

BRIEF SUMMARY OF THE INVENTION

The method and the device according to the invention serve forelectrolytic treatment of electrically mutually insulated, electricallyconductive structures on surfaces of electrically insulating foilmaterial, the electrically conducting structures not being directly inelectrical contact. It is possible as a result to treat electrolyticallystructured regions which are electrically mutually insulated. Bothexternally situated regions on the foil material and hole walls in thematerial can be treated.

DETAILED DESCRIPTION OF THE INVENTION

In order to implement the method according to the invention, the foilmaterial is unloaded from a store, for example a roller (for exampleunwound), then transported on a conveying line through a treatment unitand brought thereby in contact with treatment fluid. After passingthrough the unit, the foil material is finally loaded (for examplewound) once again onto a store, for example a roller. One possibilityconsists in transporting the material in a horizontal conveyingdirection. The conveying line shown in the drawings as flat andhorizontal could, if desired, be vertical. Such an arrangement isimplemented in so-called reel-to-reel units. For this purpose, thematerial is transported by known means, for example by rollers orcylinders. Alternatively, the foil material can also be guided in theunit via deflecting rollers and as a result can change the direction inthe unit one or more times. As a result, the longest possible route inthe unit is attained so that the treatment time is extended for a presetfeed rate of the material.

The device according to the invention has the following features:

a) at least a first and second device respectively for storing the foilmaterial, for example one roller, on which the material is stored andunwound for treatment, and one roller, on which the material is woundagain after treatment;

b) suitable transport devices, for example rollers, cylinders or otherretaining elements, such as clamps for transporting the foil material ona conveying line through a treatment unit from at least the one firststoring device to at least the one second storing device;

c) at least one device for bringing the foil material in contact with atreatment fluid, for example a treatment container into which thematerial can be introduced, or suitable nozzles, with which the liquidis supplied to the material surfaces;

d) at least one electrode arrangement, comprising respectively at leastone cathodically polarised electrode and at least one anodicallypolarised electrode, at least the one cathodically polarised electrodeand at least the one anodically polarised electrode being able to bebrought in contact with the treatment fluid; the electrodes can beeither disposed for one-sided treatment of the material on only one sideof the conveying line or, for two-sided treatment, also on both sides;the cathodically polarised electrodes and the anodically polarisedelectrodes of an electrode arrangement are orientated on one side of theconveying line;

e) at least one insulation wall between the electrodes of one electrodearrangement respectively;

f) at least one current/voltage source which is connected to theelectrode arrangements in order to produce a current flow through theelectrodes of the electrode arrangements, a galvano-rectifier or acomparable current/voltage source or a current/voltage source forproducing unipolar or bipolar current pulses being able to be used asthe current/voltage source;

g) at least the one cathodically polarised electrode and at least theone anodically polarised electrode being mutually screened by at leastthe one insulation wall in such a manner that substantially noelectrical current can flow directly between the oppositely polarisedelectrodes.

In order to implement the method according to the invention, the foilmaterial is brought in contact with the treatment fluid while beingtransported through the treatment unit and guided past at least oneelectrode arrangement, which comprises respectively at least onecathodically polarised electrode and at least one anodically polarisedelectrode. The cathodically and anodically polarised electrodes are alsobrought in contact with the treatment fluid and connected to acurrent/voltage source so that, on the one hand, a current flows betweenthe cathodically polarised electrode and an electrically conductivestructure on the material and, on the other hand, a current flowsbetween the anodically polarised electrode and the same electricallyconductive structure on the material if this structure is situatedopposite both electrodes at the same time.

If a two-sided treatment of the material is desired, electrodes must bedisposed on both sides of the material. In the case of one-sidedtreatment, it is adequate to have electrodes on one side of thematerial. The electrodes of a electrode arrangement, which comprisesrespectively at least one anodic and at least one cathodic electrode,are disposed in such a manner that they are orientated on one side ofthe material and that at least one insulation wall is disposed betweenthe electrodes.

The electrodes are electrically connected by for example agalvano-rectifier. If a plurality of electrode arrangements is used thenall of the electrode arrangements can be connected to the samegalvano-rectifier. In certain conditions, it can also be advantageoushowever to connect the individual electrode arrangements respectively toone galvano-rectifier. The galvano-rectifiers can be operated as currentsource or as voltage source.

As a consequence of the fact that an electrically conductive connectionexists by means of a conductive layer to be processed on the structuresof the material, which structures are situated opposite the cathodicallypolarised electrode or the anodically polarised electrode at the sametime, these structures are polarised respectively anodically orcathodically relative to the electrodes. As a result, electrochemicalprocesses are set in motion at these places. An electrical contact ofthe material is not required to produce a current flow in the material.The material operates as an intermediate conductor. An electrode and thestructure situated opposite this electrode on the material can beregarded as an electrolytic partial cell. One of the two electrodes ofthis partial cell is formed by the material itself and the other by theelectrode of the electrode arrangement. As a result of the fact that thematerial is situated opposite a cathodically and an anodically polarisedelectrode, a serial connection of two electrolytic partial cells of thistype is effected, said partial cells being supplied from acurrent/voltage source, for example from a galvano-rectifier.

The advantage of the method and the device according to the inventioncompared to known methods and devices resides in the fact that theequipment costs for producing a current flow in the material to betreated is a great deal less than in many known methods and devices. Inthe present case, no contacting elements need to be provided. Thematerial is polarised without contact. As a result, the deposition ofmetal, especially with a small layer thickness, can be implemented veryeconomically. Furthermore, the arrangement can be configured verysimply.

The method and the device according to the invention therefore makepossible the electrolytic treatment of electrically mutually insulated,electrically conductive metal islands (structures) at low cost.

Relative to the methods proposed for printed circuit board technologyfor metallising mutually insulated metal islands with brusharrangements, the method and device according to the invention have theadvantage that only small quantities of metal are deposited needlesslyon the cathodically polarised electrode. The frequency with which themetal must be removed from the cathodically polarised electrodes again,is in the region of a few days to a few weeks. In addition, there is noproblem of the brush electrodes becoming worn during contact with thesurfaces to be metallised and hence of abraded particles contaminatingthe treatment bath.

Since the electrodes of an electrode arrangement, which are polarisedoppositely to each other, are mutually screened in such a manner thatsubstantially no electrical current can flow directly between theseelectrodes, the efficiency of the method relative to known methods anddevices is increased by a multiple since the current yield is very muchgreater. Only when, according to the invention, an insulation wall isprovided between the oppositely polarised electrodes in the electrodearrangements, can the net effect be achieved also on the electricallyinsulated structures in that the spacing between the electrodes isadjusted according to the size of the structures to be treated, while anadequate effect level of the method is maintained. In the case of smallstructures, a small spacing is required; in the case of largerstructures, the spacing can also be larger. By means of the insulationwall, a direct current flow is prevented thereby between the oppositelypolarised electrodes (short-circuit current) and likewise a directcurrent flow from the one electrode to the region on the substrate to betreated which is situated opposite the other electrode and vice versa.

The option is also advantageous that very high currents can betransferred without difficulty to the material to be treated without theelectrically conductive surface structures on the material being heatedand damaged or even destroyed since no contact means are required.Because of the effective cooling of the material to be coated by thesurrounding treatment fluid, the specific current loading in the metallayer to be treated can be set very high, for example up to 100 A/mm².

The method and the device can be used for implementing any electrolyticprocesses: electroplating, etching, oxidising, reduction, cleaning,electrolytic assistance in non-electrolytic per se processes, forexample for starting a currentless metallising process. For example,gases can also be produced on the surfaces of the material, namelyhydrogen in a cathodic reaction and/or oxygen in an anodic reaction. Itis also possible for these individual processes to take place at thesame time, together with other methods, for example metallisingprocesses or other electrochemical processes.

Areas of application of the method or the device according to theinvention are among others:

-   -   deposition of thin metal layers;    -   transference of surface layers made of metal within a plate or        foil from one sacrificial region to another region, for example        in order to reinforce surface layers with the metal which is        obtained from the sacrificial region;    -   thinning by etching, for example the removal of a layer of        several μm from the surfaces of the material;    -   pulse etching;    -   deposition of metal with pulse current;    -   electrolytic oxidation and reduction of metallic surfaces;    -   electrolytic cleaning by anodic or cathodic reaction (for        example, by electrolytic formation of hydrogen or oxygen);    -   electrolytic deburring of perforated foils provided with        structures;    -   etch-cleaning with electrolytic assistance; and further        processes in which electrolytic assistance is advantageous.

The method and the device can be used particularly well for depositingthin metal layers, for example layers up to a thickness of 5 μm.

The following conditions among others can be set for implementing themethod according to the invention:

-   -   the type of material from which the basic conductive layer of        the material to be treated is formed;    -   the type of coating metal;    -   the type and the parameters of the electrolytic process, for        example the current density;    -   the composition of the treatment fluid;    -   the geometry of the treatment device, for example the width of        the electrode spaces in the conveying direction.

By optimal selection of combinations of the above-mentioned parameters,the electrolytic treatment can be controlled. For example, by choosing aspecific metal depositing bath it can be effected that the alreadydeposited metal is not etched off again since the metal dissolutionprocess is restricted in this case. At the same time, it can be achievedby appropriate choice of an etching bath that the metal deposition inthis bath is restricted.

In order to implement the method for etching metal surfaces on thematerial, the material is guided firstly past at least one anodicallypolarised and then at least one cathodically polarised electrode.

The method and the device can be used for metallising. For this purpose,the material is guided firstly past at least one cathodically polarisedand then at least one anodically polarised electrode. Preferably,material with structures is used for electrolytic metallising, whichstructures are provided with a surface which is insoluble duringelectrolytic metallising. For example, final layers made of metal can beformed on conductive foils, for example a tin coating on copper with themethod and the device according to the invention.

A further application of the method and the device consists in deburringthe conductive foil material after boring by means of electrolyticetching. To date, devices have been used to deburr printed circuitboards which are based on mechanical methods, for example, rotarybrushes with which the burr is removed. Mechanical methods of this typeare entirely unusable for foil materials since the foil materials wouldbe destroyed by mechanical treatment.

The principle of the method and device according to the invention isexplained subsequently with reference to

BRIEF DESCRIPTION OF DRAWING FIGS. 1 AND 2

FIG. 1 schematic illustration of the device according to the invention;and

FIG. 2 schematic illustration of the principle of the method accordingto the invention.

FURTHER DETAILED DESCRIPTION OF THE INVENTION

A bath container 2 in a treatment unit 1 is illustrated in FIG. 1 and isfilled up to the level Ni with a suitable treatment fluid F1.Electrically insulating foil material Fo with electrically mutuallyinsulated, electrically conductive structures 4 is guided through thetreatment fluid F1 in a horizontal direction Ri′ or Ri″ by means ofsuitable conveying means 3, such as for example rollers or cylinders. Inaddition, there are two electrodes 6, 7 in the bath container 2 whichare connected to a current/voltage source 8. The electrode 6 iscathodically polarised, the electrode 7 anodically polarised. Aninsulation wall 9 (for example of plastic material) is disposed betweenthe two electrodes 6, 7 and screens the two electrodes from each otherelectrically, transversely relative to the conveying direction. Thiswall 9 is preferably introduced so tightly against the film Fo that saidwall contacts or at least reaches up to said foil when passing by.

While the foil Fo is being moved past the electrodes 6, 7, thestructures 4* are polarised, and indeed anodically in the regions4*_(a), which are situated opposite the cathodically polarised electrode6, and cathodically in the regions 4*_(k), which are situated oppositethe anodic electrode 7.

If the foil Fo is guided past the electrodes 6, 7 for example in thedirection Ri′, then the structures 4 are etched. In this case, the leftregion 4*_(a) of the structure 4* is anodically polarised in theposition shown in FIG. 1 so that metal is etched away from theconductive track structure. The right region 4*_(k) of this structure 4*is, on the other hand, orientated towards the anodically polarisedelectrode 7 and hence is negatively polarised. If the treatment fluid F1contains no further electrochemically active redox pairs, hydrogen isgenerated in this region 4*_(k). In summary, metal is therefore removedfrom the structures 4. This procedure continues in the case of a singlestructure 4 for as long as this structure is situated simultaneously inthe effective regions of both oppositely polarised electrodes 6 and 7.

If the foil Fo is to be metallised, it must be transported in thedirection Ri″. In this case, a metallising bath is used as treatmentfluid F1. Firstly, the respectively right edges of the structures 4enter into the region of the cathodically polarised electrode 6 and theninto the region of the anodically polarised electrode 7. The right part4*_(k) of the structure 4* is situated opposite the anodically polarisedelectrode 7 in the position shown in FIG. 1 and thus is polarisedcathodically. On the other hand, the left part 4*_(a) of the structure4* is situated opposite the cathodically polarised electrode 6 so thatthis part is polarised anodically. If for example a conductive trackstructure, which is made of copper as the basic conductive layer, is tobe treated with tin from a tinning bath F1 which contains tin ions, thenonly oxygen is generated on the left part 4*_(a) of the structure 4*. Onthe other hand, tin is deposited on the right part 4*_(k). To sum up,tin is thus deposited on the copper structures.

Basically the same arrangement as described in FIG. 1 is shown in FIG.2, provided with a bath container 2 with electrolytic fluid F1. Thelevel of fluid F1 is designated by Ni. In addition to FIG. 1, the effectof the electrical field of the electrodes 6, 7 on the foil Fo isreproduced schematically. An insulation wall 9 is located between theelectrodes 6 and 7. The regions 4*_(a) and 4*_(k) of the metallicstructures are connected together electrically. A more positivepotential is produced at the region 4*_(a), which is situated oppositethe cathodically polarised electrode 6 so that this region is polarisedanodically. A more negative potential is produced at the region 4*_(k)by the oppositely situated anodically polarised electrode 7, so thatthis region is polarised cathodically. In the illustrated arrangementthe structure 4*_(k) is metallised when the electrolytic fluid F1 is ametallising bath. At the same time, an anodic process takes place at theanodically polarised structure 4*_(a). If the electrolytic fluid F1 is atin bath and the structures 4 are made of copper, copper is notdissolved. Instead of this, oxygen is generated at the region 4*_(a).

During the electrolytic process, both soluble and insoluble electrodescan be used as electrodes. Soluble electrodes are normally used in themetallising method so as to reform again by dissolution the metal usedin metallisation in the metallising solution. Thus, electrodes made ofmetal, which is to be deposited, are used. Insoluble electrodes are alsoinert in the treatment fluid during the current flow. For example, leadelectrodes, platinised titanium electrodes, titanium or noble metalelectrodes coated with iridium oxide can be used.

If the method and the device are used for electrolytic metallising, thena metallising bath containing metal ions is used. When using soluble,anodically polarised electrodes, the metal ions are supplied bydissolution of these electrodes. On the other hand, if insolubleelectrodes are used, then the metal ions must be supplemented either byseparate addition of suitable chemicals or for example the devicedescribed in WO 9518251 A1 is used in which metal parts are dissolved byadditional ions of a redox pair, which ions are contained in ametallising bath. In this case, an Fe²⁺/Fe³⁺ or another redox pair iscontained in the copper baths.

In a further variant of the method and device, the electrodes can bedisposed in an electrode arrangement in such a way that they areorientated on only one side of the material. In order to avoid a directcurrent flow in this case between the two electrodes, it is advantageousto dispose at least one insulation wall (for instance made of apolyimide film which is 50 μm thick) between the electrodes and to movesaid wall very near to the material. The insulation walls are preferablydisposed in such a way that they contact the material when beingtransported through the electrolytic bath or that they reach at leastdirectly up to the surfaces of the material. As a result, an especiallygood screening of the anodic electrode from the cathodic electrode isachieved.

Since small structures to be metallised must be situated opposite bothat least one cathodic and at least one anodic electrode for electrolytictreatment, the spacing between the electrodes, given an established sizeof the structures, must not exceed a specific value. Consequently, a toplimit is also established for the thickness of the insulation wall. As arule of thumb, it can be assumed that the thickness of the insulationwall should correspond at most to approximately half of the extension ofthe structures to be metallised, preferably comparing the dimensionsrespectively in the conveying direction of the material. In the case ofstructures with a width of approximately 100 μm, the thickness of theinsulation wall should not exceed 50 μm. In the case of narrowerstructures, correspondingly thin insulation walls should be used.Further insulation walls can be provided in addition between theindividual electrode arrangements in order to avoid a direct currentflow between the electrodes of further electrode arrangements which aredisposed one behind the other.

If the material is not plunged into the treatment fluid but brought incontact with the fluid by means of suitable nozzles, the isolation wallscan be totally dispensed with if the fluid regions which are in contactwith the individual electrodes do not come in contact with each other.

In an alternative method and device variant, the electrodes of anelectrode arrangement can also be disposed in such a way that they areorientated on different sides of the material. In this case, thematerial itself functions as an insulation wall between the electrodesso that the use of insulation walls between the electrodes of anelectrode arrangement can be dispensed with when the electrodes do notprotrude beyond the material. This method and device variant can beapplied when the electrically conductive regions on both sides of thematerial are connected to each other electrically. This arrangement issuitable for example for the treatment of through hole plated conductivefoils which are functional on one side. As a result of the fact that forexample material with a whole-surface electrically conductive layer isused on the side situated opposite the functional side, the cathodicallypolarised electrode can be disposed opposite this conductive layer andthe anodically polarised electrode opposite the functional side in orderto deposit metal on the conductive structures of the functional side. Atthe same time, metal is removed from the oppositely situated conductivelayer.

An electrode arrangement can extend perpendicularly or diagonally to thedirection in which the material is transported in the treatment unit,preferably over the entire treatment width of the plane in which theconveying line for the material extends. The spatial extension of theelectrode arrangements, observed in conveying direction, has asignificant effect on the duration of the electrolytic treatment. Longelectrode arrangements can be used for large structures on the material.On the other hand, very short electrode arrangements must be used whentreating very fine structures.

This can be explained in more detail with reference to FIG. 1. If thematerial Fo is moved from left to right (conveying direction Ri″; case:electroplating), the lading right edge of a structure 4* iselectroplated longer than the rear regions of the structure. As aresult, an irregular layer thickness is obtained. The maximum thicknessof the layer depends substantially upon the length of the electrodearrangement in the conveying direction Ri′, Ri″ and, furthermore, uponthe conveying rate, the current density and the dimensions of thestructures 4 in conveying direction Ri′, Ri″. Long electrodearrangements and, at the same time, long structures 4 in conveyingdirection Ri′, Ri″ result, measured absolutely, in large differences inlayer thickness in the case of a large initial layer thickness. When theelectrode arrangements have a smaller length in conveying direction Ri′,Ri″ , the differences in layer thickness become smaller. At the sametime, the treatment time is reduced. The dimensions of the electrodearrangements can therefore be adapted to requirement. In the case of thefinest conductive track structures, for example 0.1 mm pads orconductive tracks of 50 μm width, the length of the electrodearrangements should be in the sub-millimeter region.

In order to multiply the effect of the method, at least two electrodearrangements can be provided in one treatment unit and the material canbe guided past said electrode arrangements successively. The electrodesof these electrode arrangements can have an extended configuration andbe disposed substantially parallel to the conveying plane. Theelectrodes can be orientated either substantially perpendicular to theconveying direction or form an angle α≢90° to the conveying direction.Said electrodes extend preferably over the entire width of the conveyingplane covered by the material.

With an arrangement in which the electrodes form an angle α≢90° to theconveying direction, it is achieved that electrically insulated metalstructures, which are orientated both parallel to the conveyingdirection and perpendicular thereto are subjected longer to the desiredelectrolytic reaction than when α≈90° (±25°). If the angle were α≈90°,then the conductive tracks, orientated in the conveying direction and ata given conveying rate and given electrode length, would beelectrolytically treated for an adequate length of time, whileconductive tracks orientated perpendicular thereto would only be treatedin the electrode arrangement for a short period of time. This is due tothe fact that electrolytic treatment is only possible if the structureis situated at the same time opposite the anodically polarised and thecathodically polarised electrode of an electrode arrangement. In thecase of structures, which are orientated parallel to the electrodearrangement and hence to the electrodes, this contact time is short. Thereverse applies when the electrode arrangements are orientated parallelto the conveying direction (α≈0° (±25°))

The device according to the invention can also have a plurality ofelectrode arrangements with electrodes in an extended configuration, theelectrodes of the different electrode arrangements forming differentangles to the conveying direction. In particular, an arrangement of atleast two extended electrode arrangements is advantageous, the anglebetween the electrode arrangements and the conveying direction of thematerial in the treatment unit being α≢90° and the electrodearrangements being disposed approximately perpendicularly to each other.Preferably, α₁≈45° (first electrode arrangement), especially 20° to 70°,and α₂≈135° (second electrode arrangement), especially 110° to 160°.

In an especially preferred method, the electrodes are moved in anoscillating manner substantially parallel to the conveying plane.

Furthermore, there can also be provided a plurality of electrodearrangements, which are disposed parallel to each other and adjacent andhave electrodes in an extended configuration and insulation wallsdisposed respectively between said electrodes, and adjacent electrodescan be supplied respectively from a separate current/voltage source. Inthis case when for example a metallising solution is used, metal isfirstly deposited on the insulated structures of the material. Since theregions of the structures which are at the front during transportationare situated for longer in the metallising region than the rearstructures, the thickness of the metal layer on the former is greater.If the material then passes the second electrode arrangement, whichcomprises the second electrode in the first arrangement or a thirdelectrode and a further oppositely polarised electrode in the secondarrangement, then a lot of metal is removed again from the front regionsof the material and, on the rear structures, more metal is depositedthan removed. Hence to sum up, an averaging of the thickness of themetal layer on the structures is effected during treatment in the twoelectrode arrangements.

In order to achieve an especially uniform metal layer thickness withthis arrangement, the current density on the structures situatedopposite the first electrode arrangement can be adjusted to a valuewhich is approximately twice as great as the current density on thestructures situated opposite the second electrode arrangement.

In a further preferred method, the electrode arrangements can inaddition be surrounded by insulation walls. If a plurality of adjacentelectrode arrangements is used, these insulation walls are disposedbetween the electrode arrangements. Openings, which are orientatedtowards the conveying plane, are formed through these insulation walls,which surround the electrode arrangements, and through the insulationwalls, which are disposed between the electrodes.

These openings can have widths of various sizes in accordance with theexisting requirements. For example, these openings have, regarded in theconveying direction, such a width respectively that the openingsassociated with the cathodically polarised electrodes are smaller thanthe openings associated with the anodically polarised electrodes whenthe method for depositing metal on the material is used, or that theopenings associated with the cathodically polarised electrodes aregreater than the openings associated with the anodically polarisedelectrodes when the method for etching metal surfaces on the material isapplied.

It is achieved with this embodiment that the current density at theregions, situated opposite the cathodically polarised electrodes, on thematerial pieces to be treated is different from the current density atthe regions which are situated opposite the anodically polarisedelectrodes. Due to these differences, potentials of different magnitudecan be set at these regions to favor specific electrolytic processes andto repress others. Hence, it is possible for example to speed up thedeposition of metal relative to the competing dissolution of the metalin order also to deposit metals at a greater thickness on the materialin this manner. While, in the above-mentioned case, the current densityand hence the potential at the region on the material, which is situatedopposite the cathodically polarised electrode, is increased, thereoccurs there as a competing reaction, the decomposition of water(generation of oxygen). As a result, less metal is dissolved than isdeposited at the material surfaces which correspond to the anodicallypolarised electrodes. The reverse is of course true for an applicationin which metal is etched.

In order to prevent metal deposition on the cathodically polarisedelectrodes, these can be screened with ion-sensitive membranes so thatelectrolytic spaces are formed which surround the cathodically polarisedelectrodes. If ion-sensitive membranes are not used, deposited metal onthe cathodically polarised electrodes must be removed again on a dailyor weekly basis. For this purpose, for example a cathodically polarisedsurface electrode can be disposed for stripping these electrodes, themetallised electrodes being anodically polarised in this case. Thesestripping electrodes can be introduced into the electrode arrangementduring production breaks instead of the material to be treated. Acyclical exchange is also very simple with external stripping of thecathodically polarised electrodes.

Furthermore, it can be advantageous for treating the material tomodulate the electrical voltage applied to the electrodes of theelectrode arrangements in such a way that a unipolar or bipolar currentpulse sequence flows to the electrodes.

The subsequent Figures serve to further explain the invention and showin detail:

BRIEF DESCRIPTION OF DRAWINGS FIGS. 3–12

FIG. 3: a schematic illustration of the construction of an electrodearrangement;

FIG. 4: the layer thickness configuration of a structure after treatmentin the device according to FIG. 3;

FIG. 5: a schematic illustration of two electrodes of an electrodearrangement;

FIG. 6: a schematic illustration of a plurality of electrodes which areassociated with various electrode arrangements;

FIG. 7: a special arrangement of a plurality of electrode arrangementsalong a conveying route for the material in a continuous system;

FIG. 8 a: a section through a continuous system;

FIG. 8 b: a plan view of a flow unit;

FIG. 9: a lateral section through a continuous system in which thematerial is transported in a horizontal conveying plane;

FIG. 10: a plan view of a foil with copper structures and a projectionof the electrodes from a plurality of electrode arrangements;

FIG. 11: a further special arrangement of a plurality of electrodearrangements along the conveying route for the material in a continuoussystem;

FIG. 12: a schematic illustration of a reel-to-reel unit forelectrolytic treatment of foil material.

FURTHER DETAILED DESCRIPTION OF THE INVENTION

An electrode arrangement according to FIGS. 1 and 2 is eminentlysuitable for treating large metal structures. The length of theelectrodes in conveying direction determines, together with theconveying rate, the duration of the electrolytic treatment with anelectrode arrangement. In the case of large structures to be treated, alarge electrode length in conveying direction is chosen, at least ifthis concerns the process-determining electrode.

If care is taken by means of appropriate process parameters that thetreatment effect achieved firstly at the first electrode is not reversedagain or at least not entirely by treatment at the second electrode ofan electrode arrangement, then a plurality of electrode arrangementsaccording to the invention can be disposed successively in conveyingdirection, i.e. a foil is guided past a plurality of electrodearrangements successively. The respective treatment results, which areachieved with the individual electrode arrangements, accumulate. Thelength of the electrode arrangements in conveying direction must beadapted to the size of the structures to be treated. When treating smallstructures, this length must also be selected to be small. The number ofelectrode arrangements must be chosen to be correspondingly greater whena treatment outcome is required. It is always a prerequisite that thetreatment outcome is not reversed again by the respectively subsequentelectrode of an electrode arrangement. For example, an already depositedmetal layer should not be removed again when passing a subsequentcathodically polarised electrode.

In the case of very small structures to be treated, the treatment of theedge regions of structures to be treated, which are guided past theelectrodes firstly or lastly, comes to the fore. However, these edgeregions should also be electrolytically treated in as uniform a manneras possible. For this purpose, the possibility of being able to setelectrochemically “oppositely directed” reactions (for examplemetallising, stripping) in the electrode arrangement in a targetedmanner is used advantageously. With reference to FIG. 3, the veryuniform electrolytic treatment of even the smallest structures (width0.1 mm) is described.

In FIG. 3, an arrangement with two electrode arrangements is reproducedwhich have respectively anodically and cathodically polarised electrodes6′, 7′, 6″, 7″. A foil Fo with the structures 4, for example conductivetrack structures made of copper, is guided in conveying direction Rithrough a not-shown electrolytic fluid. A tin bath is used in thisexample as electrolytic fluid.

The cathodically polarised electrodes 6′, 6″ are screened byion-sensitive diaphragms 5 from the surrounding electrolytic space. As aresult, the deposition of tin on the electrodes 6′, 6″ from theelectrolytic fluid is prevented. Insulation walls 9′ or 9″ are locatedrespectively between the electrodes 6′ and 7′ or 6″ and 7″. Aninsulation wall 17 is disposed between the two electrode arrangements.The diaphragms 5 can also be dispensed with. In this case, thecathodically polarised electrodes 6′, 6″ need to be stripped from timeto time.

The structures 4 are metallised in the first electrode arrangement inwhich the electrodes 6′ and 7′ are located. As a result of the fact thatthe structures 4 are guided past the electrode arrangement from left toright, the right edge of the structures 4 is subjected for a longer timeto the electrolytic reaction than the left edge so that the depositedquantity of metal and hence the thickness of the metal layer is greaterthan on the left edge. In order to compensate at least in part for thislack of balance, the foil Fo is guided past the second electrodearrangement after passing through the first electrode arrangement. Inthis arrangement, the sequence of the cathodically polarised electrode6″ and of the anodically polarised electrode 7″ is changed relative tothe polarity of the electrodes 6′ and 7′ in the first electrodearrangement so that the left edge of the structures 4 respectively issubjected for a longer time to the electrochemical (electroplating)effect of the electrode 7″ than the respective right edge. The rightedge of the structures 4 is anodically polarised when passing thecathodically polarised electrode 6″ and hence is subjected for a longertime to the anodic reaction than the left edge of the structures 4 sothat, in this case, metal is preferably removed again on the right edge.As a result, a substantially uniformly thin layer of tin is deposited.

This result can be understood with the help of the diagram in FIG. 4 inwhich the obtained metal layer thickness d is reproduced as a functionof the length extension a of the structure 4 to be coated. This diagramwas drawn up with the condition that the current in the second electrodearrangement is half as great as in the first electrode arrangement andthat the current yield of the electrochemical reactions (metaldissolution, metal deposition) is close to 100%.

The layer thickness distribution, which can be measured after thestructures have passed through the first electrode arrangement, isdesignated by the curve I. On the left edge of the structures (a=0),practically no metal has been deposited, while on the right edge (a=A)the layer thickness D is achieved. Two processes take place when passingthe second electrode arrangement: at the left edge, in practice onlymetal is deposited (partial process, displayed by curve II). Thus, thelayer thickness D/2 is achieved in this region. In addition, in practiceonly metal is removed at the right edge (partial process, displayed bycurve III). Thus, the layer thickness at this location is reduced fromoriginally d=D to d=D/2. The intermediate regions on the structurelikewise have substantially a layer thickness of d = D/2. The resultinglayer thickness distribution is indicated in curve IV.

By optimizing the treatment bath, the metallisation can be improved evenfurther: by using a bath for metal deposition, which does not permitmetal dissolution, a greater metal layer thickness can be achieved intotal. In this case, the currents of the first and of the secondelectrode arrangement must be of equal size. The curve III shown in FIG.4 coincides in this case with the abscissa since no metal is dissolved.Therefore, a thickness D of the layer is obtained which is constant overthe total surface of the metal structures (curve IV′).

A further simplification of the arrangement according to FIG. 3 isachieved in that the central regions with the electrodes 7′, 7″ (in FIG.3) are combined so as to form one region with one electrode. In thiscase, two current/voltage sources are also required to supply current tothe electrodes with which the different currents to both partialelectrode arrangements, comprising the electrode 6′ and the electrode7′, 7″, on the one hand, and the electrode 7′, 7″ and the electrode 6″,on the other hand, can be produced. The dividing wall 17 is dropped inthis case. The mechanical assembly of the electrode arrangements isparticularly simple in this case.

The schematic assembly of the electrode arrangement in a preferredembodiment of the invention is reproduced in FIG. 5. The foil Fo withthe structures 4 is illustrated underneath the electrode arrangement(the structures 4 situated on the underside of the foil Fo areelectrolytically treated by a second electrode arrangement on theunderside of the foil). The foil Fo is guided in the conveying directionRi. The electrode arrangement comprises electrodes 6 (cathodic) and 7(anodic). Between the electrodes 6 and 7 there is an insulation wall 9which is situated in this case on the foil Fo and effects an effective,electrical screening of the field lines which emanate from theelectrodes 6 and 7. The electrodes 6 and 7 are surrounded by thecathodic space 10 and the anodic space 11 in which the electrolyticfluid F1 is located. Both spaces 10 and 11 open towards the conveyingplane in which the foil Fo is guided. Focusing of the effect of theelectrodes on a small region of the foil Fo is achieved by two smallopenings 12 _(k) and 12 _(a) a which are formed through the lateralinsulation walls 13, 14 and the insulation wall 9 between the electrodes6 and 7. This is advantageous since, as a result, the electrolytictreatment of the small structures 4 is evened out. In contrast thereto,the electrolytic treatment of small structures, when large openings 12_(a) and 12 _(k) are chosen, is irregular.

As can also be detected in FIG. 5, the electrolytic fluid F1 is fed intothe electrode arrangements from above (shown by the arrows Sr). Theelectrochemical reaction can be speeded up because of the high flowrate.

In FIG. 6 there is shown a further arrangement according to theinvention with a plurality of adjacent electrodes 6, 7′, 7″. Theelectrodes 6, 7′, 7″ are connected to the current/voltage sources 8′,8″, for example galvano-rectifiers. Insulation walls 9 are locatedbetween the electrodes. A foil Fo to be treated is moved in conveyingdirection Ri in the conveying plane. The respective electrolytic spaces,which surround the electrodes 6, 7, have openings 12 _(a), 12 _(k),which are orientated towards the conveying plane and are formed by theinsulation walls 9. These openings 12 a, 12 _(k) are of different sizes.As a result, current densities of different size are set and hence alsodifferent potentials at the regions 4, 4* on the foil Fo which aresituated opposite the openings 12 _(a), 12 _(k).

In the situation where a foil Fo provided with metallic regions 4 istreated in a metal deposition solution, the following situation arises.

As a result of the fact that the opening 12 _(k) on the cathodicallypolarised electrode 6 is smaller than the opening 12 _(a), on theanodically polarised electrode 7, a higher current density and hence ahigher potential is set at the regions 4*_(a) situated opposite thecathodically polarised electrode 6 than is set at the regions 4*_(k) ofthe treated region 4*, which regions are situated opposite theanodically polarised electrodes 7′, 7″. Consequently, the competingoxygen generation will take place also, in addition to metaldissolution, during the anodic partial process in the region of thecathodically polarised electrode 6 so that less metal is removed in thisregion 4*_(a) than the amount of metal deposited in the region 4*_(k) .In summary, a metal layer is thus formed.

In FIG. 7, a special arrangement of a plurality of electrodearrangements 18 along the conveying line for the material in acontinuous system is reproduced in plan view. The electrodes 6′, 6″, 7′,7″ in the arrangement of FIG. 1 are schematically illustrated by thecontinuous and broken straight lines. The electrode arrangements 18 areset slightly diagonally in the conveying direction Ri and extend at acorresponding length in the electrolytic unit. Each electrodearrangement 18 serves only for treating a part of the surface of thematerial to be treated. Hence, the treatment time is significantlyincreased. If the electrolytic unit has for example a length of 1.40 mand a width of 0.2 m, then, in the illustrated arrangement with fourelectrode arrangements 18, there results an increase in treatment timeof 1400 mm×4/200 mm=28. In the case of an active length of an electrodearrangement 18 of 1 mm, there results hence a treatment time ofapproximately 17 sec, at a conveying rate of for example 0.1 m/min. Withan average deposition current density at the level of 10 A/dm², thelayer thickness of deposited copper is approximately 0.6 μm. If aplurality of electrodes is used to treat partial regions of thematerial, then the layer thickness multiplies with the number ofelectrodes.

A continuous system 1 is illustrated in section in FIG. 8 a. A foilstrip Fo is transported in this case for example by cylinders and heldvertically. The strip Fo is introduced into a container 2 from the side,said container containing the treatment bath, for example ametallisation solution F1. This solution is continuously withdrawn fromthe container 2 by means of a pump 21 via suitable pipelines 20 andguided over a filter 22 before said solution is fed back into thecontainer. In addition, air can be introduced via a pipeline 23 in thecontainer 2 in order to add turbulence to the solution F1.

In FIG. 8 b, the unit 1 shown in FIG. 8 a is reproduced in a plan view,the fittings only being illustrated in part. The foil strip Fo is guidedin conveying direction Ri. The treatment fluid F1 is situated internallyof the container 2, in this case a solution which is suitable forelectrolytic etching. The strip Fo is introduced via the opening 24 andthrough squeeze rollers 25 into the container 2 and between squeezerollers 26 and through the opening 27 once again out of the container.Within the container 2, the strip Fo is guided by means of suitableguide elements 3, for example by rollers or cylinders.

In the container 2, there is a plurality of electrode arrangements,which are disposed successively and on both sides of the conveying planefor the strip Fo, said electrode arrangements being formed respectivelyfrom cathodically polarised electrodes 6′, 6″, 6″′, . . . and anodicallypolarised electrodes 7′, 7″, 7′″ . . . Insulation walls 9 are situatedbetween the electrodes. These insulation walls 9 have elastic seal films16 which make possible complete screening of the electrical fields ofthe individual electrode spaces from each other in that they contact thematerial surfaces when passing the strip Fo. The electrodes 6′, 6″, 6″′,. . . , 7′, 7″, 7″′, are connected to a galvano-rectifier 8, theconnections of the electrodes shown on the right in FIG. 8 b to therectifier not being illustrated. Each electrode arrangement can also besupplied from separate rectifiers.

When the strip Fo is guided for example first past an anodicallypolarised electrode and then past a cathodically polarised electrode,metal is electrolytically removed.

In FIG. 9, a horizontal unit for electrolytic treatment of foil strip Fois illustrated in lateral section. The container 2 contains thetreatment fluid F1. The foil Fo to be treated is guided horizontally inthe treatment fluid F1 past the electrode arrangements in conveyingdirection Ri. The electrode arrangements in turn comprise respectivelycathodically polarised electrodes 6′, 6″, 6″′, . . . and anodicallypolarised electrodes 7′, 7″, 7″′, . . . The electrode arrangements aredisposed on both sides of the conveying plane in which the foil Fo isguided.

In the present case, insulation rollers 28 with sealing lips are used toinsulate the electrodes 6′, 6″, 6″′, . . . , 7′, 7″, 7″′, . . . fromeach other. Instead of insulation rollers 28, insulation walls 9 withseal films 16 can also be used.

In the right part of FIG. 9, an alternative embodiment and arrangementof the electrodes 6″′, 7″′ relative to the insulation walls 9 and sealfilms 16 is illustrated.

In FIG. 10, a plan view of a foil Fo is illustrated which has metalsacrificial regions 29 and regions 30 provided with metal structures(structures not shown), which are connected to each other electrically.This foil Fo can be treated for example in a horizontal unit by beingplunged into the treatment fluid and being guided past the electrodearrangements according to the invention. The electrodes 6, 7 of theelectrode arrangements are illustrated here in projection on the foilFo. The anodically polarised electrodes 7 are orientated on thestructured regions 30 and designated by “Θ” and the cathodicallypolarised electrodes 6 are orientated on the sacrificial regions 29,which are made of metal and are designated by “θ”. Insulation walls 9are disposed between the electrodes 6 and 7. The insulation walls 9 andthe electrodes 6, 7 are only indicated in the illustration of FIG. 10,this detail concerning a section representation through the plane ofprojection of the Figure.

The material piece is guided in one of the conveying directions Ri′ andRi″ . The sacrificial regions 29, which are made of metal, arecontinuously guided past the cathodically polarised electrodes 6 andthus are dissolved. The structured regions 30, on the other hand, aremetallised since they are guided past the electrodes 7. By means of thisarrangement, it is possible for a metal to be deposited which isidentical to the metal from which the structured regions are made.

A further preferred device according to the invention is illustratedschematically in FIG. 11. The material is guided past the electrodearrangements in conveying direction Ri, said electrode arrangementscomprising respectively extended electrodes 6′, 6″, 6″′, . . . and 7′,7″, 7″′, . . . The electrode arrangements with the electrodes form anangle α₁ or an angle α₂ relative to the conveying direction Ri. As aresult, the effect of the treatment time of structures which areorientated differently relative to the conveying direction Ri iscompensated for. Since, in the case of conductive foils, the conductivetracks usually extend parallel or perpendicular to a lateral edge of thefoils and hence parallel or perpendicular to the conveying direction Ri,a treatment time of equal length is achieved for conductive tracks ofboth orientations by means of the illustrated orientation of theelectrode arrangements, as long as these conductive tracks of bothorientations have the same length.

A further treatment unit 1 is schematically illustrated in FIG. 12 inwhich long foil strips Fo can be electrolytically treated. Units 1 ofthis type are designated as reel-to-reel units.

The strip Fo is unwound from a first roller 15′ which serves as a storefor the foil strip Fo, and wound onto a second roller 15″ when the stripis transported through the unit 1 in conveying direction Ri′. When thestrip Fo is transported through the unit 1 in conveying direction Ri″ ,the roller 15″ serves to unwind the strip and the roller 15′ to wind upthe strip Fo after rinsing and drying.

Furthermore, the treatment unit 1 comprises a container 2 in which atreatment fluid F1 is situated. The strip Fo is guided via a pluralityof deflection rollers 3 after entering the container 2, said rollers 3having no electrical function, and said strip is thereby guided past amultiplicity of electrode arrangements, which comprise respectively acathodically polarised electrode 6 and an anodically polarised electrode7. The cathodically polarised electrodes 6 are designated by “θ” and theanodically polarised electrodes 7 by “⊕”. In the present case, theelectrode arrangements are only disposed on one surface of the strip Fo.If both surfaces of the strip Fo are to be treated, there must beelectrode arrangements located on both sides of the insulating strip.

A portion of an electrode arrangement with the strip Fo which is guidedpast said electrode arrangement is illustrated in a detail in FIG. 12.The cathodically polarised electrode 6 is separated from the anodicallypolarised electrode 7 by an insulation wall 9.

Reference symbols: 1 treatment unit 2 bath container 3 guide element forthe foil material Fo 4 metallic structure on the foil material Fo 4*treated metallic structure 4 4*_(a) anodically treated metallicstructure 4 4*_(k) cathodically treated metallic structure 4 5 diaphragm6, 6′, 6″, 6′″ cathodically polarised electrodes 7, 7′, 7″, 7′″anodically polarised electrodes 8, 8′, 8″ current/voltage sources 9insulation wall 10 cathodic space 11 anodic space 12 opening of theelectrode arrangement to the bath container 12_(k) opening to thecathodically polarised electrode 12_(a) opening to the anodicallypolarised electrode 13 insulating lateral wall of the electrodearrangement 14 insulating lateral wall of the electrode arrangement 15′,15″ storage rollers for winding/unwinding foil strips Fo 16 seal film 17insulation wall between two electrode arrangements 18 electrodearrangement 20 electrolytic line 21 pump 22 filter 23 air supply 24inlet opening 25 squeeze roller 26 squeeze roller 27 outlet opening 28insulation roller 29 sacrificial region 30 structured region Fosheet/foil material piece Ri, Ri′, Ri″ conveying direction Fl treatmentfluid Sr flow direction of the treatment fluid Fl

1. Method for electrolytic treatment of electrically mutually insulated,electrically conductive structures (4) on surfaces of an electricallyinsulating foil material (Fo), comprising the steps of: a) unloading thefoil material (Fo) from a store (15′, 15″); b) transporting the foilmaterial (Fo) on a conveying line through a treatment unit (1) andthereby bringing the foil material in contact with a treatment fluid(F1); c) during the transporting, guiding the foil material past atleast one electrode arrangement, which comprises respectively at leastone cathodically polarised electrode (6) and at least one anodicallypolarised electrode (7), the at least one cathodically polarisedelectrode (6) and the at least one anodically polarised electrode (7)being brought in contact with the treatment fluid (F1) and beingconnected to a current/voltage source (8) flowing a current through theelectrodes (6,7) and the electrically conductive structures (4) so thatthe electrolytic treatement takes place at the surfaces of the material(Fo), furthermore the electrodes (6,7) of an electrode arrangement beingdisposed in such a manner that they are oriented on one side of thematerial (Fo), and at least one insulation wall (9) being disposedbetween the electrodes (6,7) wherein the guiding of the foil materialpast the at least one electrode arrangement does not require electricalcontact of the foil material with any electrodes in order to effect theelectrolytic treatment; d) arranging the at least one cathodicallypolarised electrode and the at least one anodically polarised electrodein the at least one electrode arrangement to match the size of theelectrically mutually insulated, electrically conductive structures,such that electric field lines emanating from the at least onecathodically polarised electrode and from the at least one anodicallypolarised electrode are effective to electrolytically treat a same oneof the electrically mutually insulated, electrically conductivestructures; and e) finally loading the foil material back onto a store(15′,15″).
 2. Method according to claim 1, characterized in that atleast the one insulation wall (9) is disposed in such a manner that itcontacts the material (Fo) during transportation through the treatmentunit (1) or that it at least reaches directly up to the material (Fo).3. Method according to one of the preceding claims 1–2, characterized inthat the material (Fo) is guided successively past at least twoelectrode arrangements.
 4. Method according to one of the precedingclaims 1–2, characterized in that the electrodes (6, 7) have an extendedconfiguration and are disposed substantially parallel to a plane inwhich the material (Fo) is transported.
 5. Method according to claim 4,characterized in that the electrodes (6, 7) extend approximately overthe entire width of the material (Fo) and substantially perpendicular tothe direction (Ri) in which the material (Fo) is transported.
 6. Methodaccording to claim 4, characterized in that the electrodes (6, 7) forman angle α≢90° to the direction (Ri) in which the material (Fo) istransported.
 7. Method according to one of the preceding claims 1–2,characterized in that the material (Fo) is guided past at least twoelectrode arrangements with electrodes (6, 7) in an extendedconfiguration, the electrodes (6, 7) of different electrode arrangementsforming different angles to the direction (Ri) in which the material(Fo) is transported.
 8. Method according to one of the preceding claims1–2, further comprising the step of moving the electrodes (6,7) in anoscillating manner substantially parallel to the plane in which thematerial (Fo) is transported.
 9. Method according to one of thepreceding claims 1–2, wherein the method for electrolytic treatment isapplied for depositing metal on the material (Fo) wherein theelectrically mutually insulated, electrically conductive structures (4)comprise at least one metal surface, characterized in that the at leastone insulation wall includes insulation walls (13,14), and in that theat least one electrode arrangement is surrounded by the insulation walls(13,14), in that openings (12 _(k), 12 _(a)) to the at least oneelectrode arrangement, which openings are oriented towards the surfacesof the material (Fo), are formed by the insulation walls (13,14) andinsulation walls (9), which are disposed between the electrodes (6,7),and in that the at least one cathodically polarised electrode includescathodically polarised electrodes (6), and in that the at least oneanodically polarised electrode includes anodically polarised electrodes(7), and in that the openings (12 _(k), 12 _(a)), observed in aconveying direction (Ri), have respectively such a width that theopenings (12 _(k)), which are associated with the cathodically polarisedelectrodes (6), are smaller than the openings (12 _(a)), which areassociated with the anodically polarised electrodes (7)
 10. Methodaccording to one of the preceding claims 1–2, characterized in that aplurality of electrode arrangements, which are disposed parallel to eachother and adjacent, are provided with the electrodes (6,7) arranged inan extended configuration and that the electrodes (6,7), which areadjacent to each other, are connected respectively to thecurrent/voltage source (8).
 11. Method according to claim 10,characterized in that the current density at the structures (4), whichare situated opposite a first electrode arrangement, is setapproximately twice as great as the current density at the structures(4), which are situated opposite a second electrode arrangement. 12.Method according to one of the preceding claims 1–2, characterized inthat the at least one cathodically polarised electrode includes aplurality of cathodically polarised electrodes, and in that electrolyticspaces (10), which surround the cathodically polarised electrodes (6),are screened by ion-sensitive membranes (5).
 13. Method according to oneof the preceding claims 1–2, characterized in that the electricalcurrent is modulated in such a way that a unipolar or bipolar currentpulse sequence flows through the electrodes (6,7) and the surfaces ofthe material (Fo).
 14. Method according to one of the preceding claims1–2, wherein the method for electrolytic treatment is applied foretching at least one metal surface on the material (Fo), wherein theelectrically mutually insulated, electrically conductive structures (4)comprise the at least one metal surface, characterized in that the atleast one insulation wall includes insulation walls (13,14), and in thatthe at least one electrode arrangement is surrounded by the insulationwalls (13,14), in that openings (12 _(k), 12 _(a)) to the at least oneelectrode arrangement, which openings are oriented towards the surfacesof the material (Fo), are formed by the insulation walls (13,14) andinsulation walls (9), which are disposed between the electrodes (6,7),and in that the at least one cathodically polarised electrode includescathodically polarised electrodes (6), and in that the at least oneanodically polarised electrode includes anodically polarised electrodes(7), and in that the openings (12 _(k), 12 _(a)), observed in aconveying direction (Ri), have respectively such a width that theopenings (12 _(k)), which are associated with the cathodically polarisedelectrodes (6), are larger than the openings (12 _(a)), which areassociated with the anodically polarised electrodes (7).
 15. The methodaccording to claim 1, wherein the electrolytic treatment comprisesdepositing metal on the foil material (Fo), and wherein during said stepof guiding the foil material past at least one electrode arrangement thefoil material (Fo) is first guided past the at least one cathodicallypolarised electrode (6) and then past the at least one anodicallypolarised electrode (7).
 16. The method of claim 15, wherein theelectrically mutually insulated, electrically conductive structures (4)comprise copper surfaces and wherein the electrolytic treatmentcomprises depositing tin on the copper surfaces.
 17. The methodaccording to claim 1, wherein the electrically mutually insulated,electrically conductive structures (4) comprise metal surfaces, whereinthe electrolytic treatment comprises etching the metal surfaces, andwherein during said step of guiding the foil material past at least oneelectrode arrangement the foil material (Fo) is first guided past the atleast one anodically polarised electrode (7) and then past the at leastone cathodically polarised electrode (6).
 18. Device for electrolytictreatment of electrically mutually insulated, electrically conductivestructures (4) on surfaces of electrically insulating foil material(Fo), which has the following features; a) at least a first and secondmeans (15′, 15″) respectively for storing the foil material (Fo); b)transport means (3), for transporting the foil material (Fo) on aconveying line through a treatment unit (1) from at least the one firststoring means (15′, 15″) to at least the one second storing means (15′,15″) for the material (Fo); c) at least one means for bringing the foilmaterial (Fo) in contact with a treatment fluid (F1) when the treatmentfluid is applied to the device; d) at least one electrode arrangement,which comprises respectively at least one cathodically polarisedelectrode (6) and at least one anodically polarised electrode (7), theat least one cathodically polarised electrode (6) and the at least oneanodically polarised electrode (7) adapted to make contact with thetreatment fluid (F1) when the treatment fluid is applied to the device,the at least one cathodically polarised electrode (6) and the at leastone anodically polarised electrode (7) of an electrode arrangement beingoriented on one side of the conveying line; e) at least one insulationwall (9) between the electrodes (6, 7) of the at least one electrodearrangement respectively; and f) at least one current/voltage source (8)which is connected to the electrode arrangement in order to produce acurrent flow through the electrodes (6, 7) of the arrangement; g) theelectrodes (6, 7) being mutually screened by at least the one insulationwall in such a manner that substantially no electrical current can flowdirectly between the oppositely polarised electrodes (6, 7); and h)wherein the transport means includes means for guiding the foil materialpast the electrodes to effect the electrolytic treatment of the foilmaterial without requiring electrical contact of the foil material withany electrode, characterized in that the electrodes (6, 7) have anextended configuration and are disposed substantially parallel to aplane in which the material (Fo) is transported, characterized in thatthe electrodes (6, 7) form an angle α≢90° to the direction (Ri) in whichthe material (Fo) is transported.
 19. Device for electrolytic treatmentof electrically mutually insulated, electrically conductive structures(4) on surfaces of electrically insulating foil material (Fo), which hasthe following features; a) at least a first and second means (15′, 15″)respectively for storing the foil material (Fo); b) transport means (3),for transporting the foil material (Fo) on a conveying line through atreatment unit (1) from at least the one first storing means (15′, 15″)to at least the one second storing means (15′, 15″) for the material(Fo); c) at least one means for bringing the foil material (Fo) incontact with a treatment fluid (F1) when the treatment fluid is appliedto the device; d) at least one electrode arrangement, which comprisesrespectively at least one cathodically polarised electrode (6) and atleast one anodically polarised electrode (7), the at least onecathodically polarised electrode (6) and the at least one anodicallypolarised electrode (7) adapted to make contact with the treatment fluid(F1) when the treatment fluid is applied to the device, the at least onecathodically polarised electrode (6) and the at least one anodicallypolarised electrode (7) of an electrode arrangement being oriented onone side of the conveying line; e) at least one insulation wall (9)between the electrodes (6, 7) of the at least one electrode arrangementrespectively; and f) at least one current/voltage source (8) which isconnected to the electrode arrangement in order to produce a currentflow through the electrodes (6, 7) of the arrangement; g) the electrodes(6, 7) being mutually screened by at least the one insulation wall insuch a manner that substantially no electrical current can flow directlybetween the oppositely polarised electrodes (6, 7); and h) wherein thetransport means includes means for guiding the foil material past theelectrodes to effect the electrolytic treatment of the foil materialwithout requiring electrical contact of the foil material with anyelectrode, characterized in that there are provided at least twoelectrode arrangements with electrodes (6, 7) in an extendedconfiguration, the electrodes (6, 7) of different electrode arrangementsforming different angles to the direction (Ri) in which the material(Fo) is transported.
 20. Device for electrolytic treatment ofelectrically mutually insulated, electrically conductive structures (4)on surfaces of electrically insulating foil material (Fo), which has thefollowing features; a) at least a first and second means (15′, 15″)respectively for storing the foil material (Fo); b) transport means (3),for transporting the foil material (Fo) on a conveying line through atreatment unit (1) from at least the one first storing means (15′, 15″)to at least the one second storing means (15′, 15″) for the material(Fo); c) at least one means for bringing the foil material (Fo) incontact with a treatment fluid (F1) when the treatment fluid is appliedto the device; d) at least one electrode arrangement, which comprisesrespectively at least one cathodically polarised electrode (6) and atleast one anodically polarised electrode (7), the at least onecathodically polarised electrode (6) and the at least one anodicallypolarised electrode (7) adapted to make contact with the treatment fluid(F1) when the treatment fluid is applied to the device, the at least onecathodically polarised electrode (6) and the at least one anodicallypolarised electrode (7) of an electrode arrangement being oriented onone side of the conveying line; e) at least one insulation wall (9)between the electrodes (6, 7) of the at least one electrode arrangementrespectively; and f) at least one current/voltage source (8) which isconnected to the electrode arrangement in order to produce a currentflow through the electrodes (6, 7) of the arrangement; g) the electrodes(6, 7) being mutually screened by at least the one insulation wall insuch a manner that substantially no electrical current can flow directlybetween the oppositely polarised electrodes (6, 7); and h) wherein thetransport means includes means for guiding the foil material past theelectrodes to effect the electrolytic treatment of the foil materialwithout requiring electrical contact of the foil material with anyelectrode, characterized in that at least the one insulation wall (9) isdisposed in such a manner that it contacts the material (Fo) duringtransportation through the treatment unit (1) or that it at leastreaches directly up to the material (Fo), characterized in that theelectrodes (6, 7) have an extended configuration and are disposedsubstantially parallel to a plane in which the material (Fo) istransported, characterized in that the electrodes (6, 7) form an angleα≢90° to the direction (Ri) in which the material (Fo) is transported.21. Device for electrolytic treatment of electrically mutuallyinsulated, electrically conductive structures (4) on surfaces ofelectrically insulating foil material (Fo), which has the followingfeatures; a) at least a first and second means (15′, 15″) respectivelyfor storing the foil material (Fo); b) transport means (3), fortransporting the foil material (Fo) on a conveying line through atreatment unit (1) from at least the one first storing means (1 5′, 15″)to at least the one second storing means (15′, 15″) for the material(Fo); c) at least one means for bringing the foil material (Fo) incontact with a treatment fluid (F1) when the treatment fluid is appliedto the device; d) at least one electrode arrangement, which comprisesrespectively at least one cathodically polarised electrode (6) and atleast one anodically polarised electrode (7), the at least onecathodically polarised electrode (6) and the at least one anodicallypolarised electrode (7) adapted to make contact with the treatment fluid(F1) when the treatment fluid is applied to the device, the at least onecathodically polarised electrode (6) and the at least one anodicallypolarised electrode (7) of an electrode arrangement being oriented onone side of the conveying line; e) at least one insulation wall (9)between the electrodes (6, 7) of the at least one electrode arrangementrespectively; and f) at least one current/voltage source (8) which isconnected to the electrode arrangement in order to produce a currentflow through the electrodes (6, 7) of the arrangement; g) the electrodes(6, 7) being mutually screened by at least the one insulation wall insuch a manner that substantially no electrical current can flow directlybetween the oppositely polarised electrodes (6, 7); and h) wherein thetransport means includes means for guiding the foil material past theelectrodes to effect the electrolytic treatment of the foil materialwithout requiring electrical contact of the foil material with anyelectrode, characterized in that at least the one insulation wall (9) isdisposed in such a manner that it contacts the material (Fo) duringtransportation through the treatment unit (1) or that it at leastreaches directly up to the material (Fo), and characterized in thatthere are provided at least two electrode arrangements with electrodes(6, 7) in an extended configuration, the electrodes (6, 7) of differentelectrode arrangements forming different angles to the direction (Ri) inwhich the material (Fo) is transported.
 22. Device for electrolytictreatment of electrically mutually insulated, electrically conductivestructures (4) on surfaces of electrically insulating foil material(Fo), which has the following features; a) at least a first and secondmeans (15′, 15″) respectively for storing the foil material (Fo); b)transport means (3), for transporting the foil material (Fo) on aconveying line through a treatment unit (1) from at least the one firststoring means (15′, 15″) to at least the one second storing means (15′,15″) for the material (Fo); c) at least one means for bringing the foilmaterial (Fo) in contact with a treatment fluid (F1) when the treatmentfluid is applied to the device; d) at least one electrode arrangement,which comprises respectively at least one cathodically polarisedelectrode (6) and at least one anodically polarised electrode (7), theat least one cathodically polarised electrode (6) and the at least oneanodically polarised electrode (7) adapted to make contact with thetreatment fluid (F1) when the treatment fluid is applied to the device,the at least one cathodically polarised electrode (6) and the at leastone anodically polarised electrode (7) of an electrode arrangement beingoriented on one side of the conveying line, the at least onecathodically polarised electrode and the at least one anodicallypolarised electrode being arranged in the at least one electrodearrangement to match the size of the electrically mutually insulated,electrically conductive structures, such that electric field linesemanating from the at least one cathodically polarised electrode andfrom the at least one anodically polarised electrode are effective toelectrolytically treat a same one of the electrically mutuallyinsulated, electrically conductive structures; e) at least oneinsulation wall (9) between the electrodes (6, 7) of the at least oneelectrode arrangement respectively; f) at least one current/voltagesource (8) which is connected to the electrode arrangement in order toproduce a current flow through the electrodes (6, 7) of the arrangement;g) the electrodes (6, 7) being mutually screened by at least the oneinsulation wall in such a manner that substantially no electricalcurrent can flow directly between the oppositely polarised electrodes(6, 7); and h) wherein the transport means includes means for guidingthe foil material past the electrodes to effect the electrolytictreatment of the foil material without requiring electrical contact ofthe foil material with any electrode.